tetrahydrogestrinone

Tetrahydrogestrinone, also known as THG or less technically The Clear, is an anabolic steroid chemically similar to gestrinone and trenbolone. THG is a potent agonist for androgen receptors, estimated to be at least 10 times as potent as the comparable steroid trenbolone, meaning that it builds muscle and burns fat extremely quickly at very small dosages (about 5mg or "just a few drops under the tongue"). Unfortunately for the people using it, it is also an extremely potent agonist for progesterone receptors, so it's also likely to halt natural testosterone production, leading to significant side effects.

Although inventions like THG have landed him in prison a few times, Patrick Arnold insists that what he does is admirable. He was bullied at a young age due to his "nerdy" obsession with chemistry, and as a result became obsessed with self-improvement. During high school he worked out extensively and created his own protein bars, but was frustrated by the lack of visible muscle mass. After sampling steroids for the first time in university, he devoted his life to creating what he calls "performance enhancers", and insists that his drugs have been "given a bad rap". Most people disagree.

[S]ome steroid precursors are clearly outside the scope of the dietary supplement definition and are subject to regulation as drugs because they are intended to affect the structure or function of the body. For example, FDA considers tetrahydrogestrinone ... a new drug under [the Food, Drug, and Cosmetic Act]. Our analysis demonstrates that this is a purely synthetic, non-naturally occurring, highly potent anabolic steroid. It is a designer steroid in the truest sense. --John M. Taylor, Associate Commissioner for Regulatory Affairs